Step 2: Building the Grow Bed
Start by building two 8'x2'x8'' grow boxes with the 2''x4''s and plywood for the base. Line the entire inside with pond liner and fill with the pea gravel. Mount the beds on the 4''x4'' posts with the carriage bolts and position them on top of each other with easy access to both and ample spaces between them for plants to trellis and mature. DO NOT MOUNT THE BEDS FLAT. The beds must be mounted on angles (around 5 deg. from flat) to allow for the water to flow down them and back into the fish tank. The top bed should be higher towards the fish-food tanks; and the lower bed should be lower towards the fish tank.
Cut a hole in the bottom of the top bed (on the end that is angled down) for the 1'' PVC pipe to allow for the water to flow from the top bed to the bottom bed. Cut another hole in the side (although at the bottom) of the bottom bed for the 1'' PVC pipe to allow for the water to flow back into the fish tank.